I am not sure whether these castings are originals or copies but it probably doesn't matter as the originals weren't especially well finished but interesting to see that the reserves wasn't met @ £2,417.70. (Original castings seem to have a faint Nardi symbol stamped on the bridging manifold.)
http://www.ebay.co.uk/itm/331689739590?_trksid=p2055119.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT40
A 2nd carb (or a pair) needs to be sourced and asking prices at Padova were min €3,400 for a DCL and higher for a 40DCZ. Also the gaskets, throttle linkage and airbox casting need to be sourced. Then you need a modified camshaft to get the best out of the twin carbs. Quite an expensive exercise but they do look nice and give more power and the engine seems to rev more freely over 5,000rpm.
Chris